Transmission question.

[Hotrod1952]

Ok everyone. I am sure this has been discussed. I have read several pieces on the internet and have more questions now than before I started. My story:
1999 L31 Suburban with a 4L60E. Recent rebuild on the motor. Now transmission is getting weak. I have in my inventory a low miles 4L60E from a 4.3L Olds Bravada 1999. This is what I believe to be true.

1) I can use either torque converter. Just the V6 has a higher stall.
2) The basic drive section clutches etc are the same.
3) I would upgrade it with the V-8 or Corvette servo.
4) Anything different in the valve body?